BSC3052 CONSERVATION BIOLOGY FSU EXAM 2 (ACTUAL
2025/2026) QUESTIONS & VERIFIED ANSWERS
Demographic Stochasticity - -Answers----- Extinction may
occur due to order of births and deaths
- Increases extinction risk and is strongest at small population
sizes
- Probabilistic births and deaths matter
+ Example 1:
- 50% probability of 1 female offspring
- 30% probability of dying every year
- Probability of no female babies = 0.5
- Probability of death = 0.3
- Probability of extinction = 0.3 x 0.5 = 0.15 = 15%
+ Example 2:
- Same probabilities as example 1
- Best case scenario, she survives and has one daughter; so
now N = 2
- Probability both die next year = 0.3 x 0.3 = 0.09
- Probability both do not breed = 0.5 x 0.5 = 0.25
- Probability of extinction = 0.09 x 0.25 = 0.0225 or 2.25%
Which stochastic processes would increase extinction rate for
a MEDIUM sized population? - -Answers----- Environmental
stochasticity
2025/2026) QUESTIONS & VERIFIED ANSWERS
Demographic Stochasticity - -Answers----- Extinction may
occur due to order of births and deaths
- Increases extinction risk and is strongest at small population
sizes
- Probabilistic births and deaths matter
+ Example 1:
- 50% probability of 1 female offspring
- 30% probability of dying every year
- Probability of no female babies = 0.5
- Probability of death = 0.3
- Probability of extinction = 0.3 x 0.5 = 0.15 = 15%
+ Example 2:
- Same probabilities as example 1
- Best case scenario, she survives and has one daughter; so
now N = 2
- Probability both die next year = 0.3 x 0.3 = 0.09
- Probability both do not breed = 0.5 x 0.5 = 0.25
- Probability of extinction = 0.09 x 0.25 = 0.0225 or 2.25%
Which stochastic processes would increase extinction rate for
a MEDIUM sized population? - -Answers----- Environmental
stochasticity
